This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. LITTLEJ is a computer program for calculating reduced spectral densities using the slowly relaxing local structure (SRLS) model. These reduced spectral densities can be used to calculate various NMR observables, such as T1 and T2. A service request was received from Dr Fushman to use LITTLEJ program to analyze the overall and inter-domain motions in his dual-domain (di-ubiquitin) system. This service may eventually lead to a collaboration project